Ipsos MORI survey suggests the Nationalists are on course to win all 59 seats
in Scotland as Nicola Sturgeon warns Ed Miliband he will have to 'change his
tune' over a deal.

The SNP is on course to win an unprecedented clean sweep of all 59 Scottish seats in next week’s general election, according to an astonishing opinion poll predicting Labour is facing extinction in its former fiefdom.

The Ipsos MORI survey for STV News put support for the Nationalists on 54 per cent, up two per cent since it last conducted a poll in January, with backing for Labour dropping four points to 20 per cent.

Support for the Conservatives has increased five points to 17 per cent, while backing for the Liberal Democrats is up one point to five per cent and the Green Party is down two points to two per cent.

SNP on course for total victory in latest Scotland polling

According to the Electoral Calculus website, this result would translate into the SNP winning every seat in Scotland, severely undermining Ed Miliband’s claim that he can enter Downing Street without striking a deal with the Nationalists.

Professor John Curtice, Scotland’s leading psephologist, agreed the findings would mean Labour being wiped out but predicted the SNP would get 58 seats as Alistair Carmichael, the Lib Dem Scottish Secretary, would hold his Orkney and Shetland constituency.

Two-thirds of Scots (69 per cent) think the SNP having influence over the UK Government would be good for Scotland, with six out of ten considering that it would be beneficial for the UK as a whole.

However, most supporters of the three main Unionist parties thought it would be a “bad thing” for the UK. Around a third of Tory and Lib Dem supporters said they would consider voting tactically for Labour if Mr Miliband's party had a chance of winning in their constituencies.

Ms Sturgeon has a positive approval rating of 48, compared to minus 34 for David Cameron, minus 31 for Mr Miliband, minus 39 for Nick Clegg and minus 19 for Jim Murphy, the Scottish Labour leader.

Nicola Sturgeon has warned Ed Miliband he would have to change his tune

The historic collapse in support for Labour in Scotland comes only five years after it won 41 Westminster seats compared to the SNP’s six.

The poll found 80 per cent of Scots are certain to vote this time, 16 points higher than in the 2010 general election. This is thought to be a legacy of last year’s referendum, when 85 per cent of the population voted.

In a speech in Glasgow, she argued that the “real democratic outrage” was figures like Sir John Major arguing that MPs democratically elected by the Scottish people have “no right” to influence the UK Government.

She has insisted that she would not use a clean sweep as justification to push for a second independence referendum, but refused to say whether she thought another Tory-led Government with few or no MPs in Scotland would have a democratic mandate to rule in Scotland.

Alex Salmond said after the 2010 election that the Coalition had “not a scintilla of a mandate” to govern in Scotland after the Lib Dems won 11 seats and the Tories one.

Reacting to the poll’s prediction of a clean sweep, Ms Sturgeon urged her supporters not to be complacent about victory. She tweeted: “Forget polls – only votes win elections. The more seats the SNP win, the stronger Scotland will be. Let’s keep working hard.”

Earlier, speaking in front of an audience of Scottish businesswomen, she said Labour would "have to change their tune if the voters, as all the polls suggest they will, deliver a parliament of minorities, with no one party having an overall majority".

Ms Sturgeon said: “A vote in Paisley counts just as much as one in Preston, a ballot in Kirkcaldy as much as one in Carlisle and a cross in a box in Renfrewshire matters just as much as one in Oxfordshire.

Anything else would be an affront to the democratic principles which all of us, from all parties, should hold dear.” But she then argued it was "wrong" that the Conservatives can govern in Scotland with just one MP north of the Border.

"So, this time, let's try and be part of getting them out completely but then using our voice to make sure they are replaced with something better … That's where SNP MPs can have a big, big influence,” Ms Sturgeon said.

Nicola Sturgeon has argued the SNP will exert major influence in a hung parliament

Speaking at a campaign stop in Glasgow, Mr Murphy said the poll was “fantastic news for David Cameron” and would mean the Prime Minister “clinging on to power.”

Jackson Carlaw, Scottish Tory deputy leader, said: “With a week to go before we vote, this poll shows that the Scottish Conservatives are the pro-UK party which has won the arguments in the campaign and is now gaining support.

“If people want a strong Unionist party that can take on the SNP, they have to vote for it. They have to vote Scottish Conservative. Ruth Davidson has exceeded all expectations in the campaign and she's the one with the momentum going into the last seven days."

Willie Rennie, the Scottish Lib Dem leader, said he remained “confident” that voters will back his party in the 11 seats they are defending when they examine “the SNP’s plans to borrow even more than Labour as they put the country into further uncertainty with their second referendum plans.”